const CC = Components.Constructor;
const BinaryInputStream = CC(
  "@mozilla.org/binaryinputstream;1",
  "nsIBinaryInputStream",
  "setInputStream"
);

function handleRequest(request, response) {
  response.setHeader("Content-Type", "text/plain", false);

  var body = new BinaryInputStream(request.bodyInputStream);

  var avail;
  var bytes = [];
  while ((avail = body.available()) > 0) {
    Array.prototype.push.apply(bytes, body.readByteArray(avail));
  }

  var data = String.fromCharCode.apply(null, bytes);
  response.bodyOutputStream.write(data, data.length);
}
